• Hansen, Michael Ryan
• Hennersdorf, Felix
• Weigand, Jan J.
• Guerrero-León, L. Andrés
• Arisnabarreta, Nicolás
• Böckmann, Steffen
• Melidonie, Jason
• Zheng, Wenhao
• Obermann, Sebastian
• Feng, Xinliang
• Feyter, Steven De
• Beljonne, David
• Wang, Hai I.
• Ma, Ji
• Osella, Silvio
• Bonn, Mischa

Abstract

<p>Precise synthesis of graphene nanoribbons (GNRs) is of great interest to chemists and materials scientists because of their unique opto-electronic properties and potential applications in carbon-based nanoelectronics and spintronics. In addition to the tunable edge structure and width, introducing curvature in GNRs is a powerful structural feature for their chemi-physical property modification. Here, we report an efficient solution synthesis of the first pyrene-based GNR (PyGNR) with curved geometry via one-pot K-region oxidation and Scholl cyclization of its corresponding well-soluble tetrahydropyrene-based polyphenylene precursor. The efficient A₂B₂-type Suzuki polymerization and subsequent Scholl reaction furnishes up to ∼35 nm long curved GNRs bearing cove- and armchair-edges. The construction of model compound 1, as a cutout of PyGNR, from a tetrahydropyrene-based oligophenylene precursor proves the concept and efficiency of the one-pot K-region oxidation and Scholl cyclization, which is clearly revealed by single crystal X-ray diffraction analysis. The structure and optical properties of PyGNR are investigated by Raman, FT-IR, solid-state NMR, STM and UV-Vis analysis with the support of DFT calculations. PyGNR exhibits a narrow optical bandgap of ∼1.4 eV derived from a Tauc plot, qualifying as a low-bandgap GNR. Moreover, THz spectroscopy on PyGNR estimates its macroscopic charge mobility μ as ∼3.6 cm² V⁻¹ s⁻¹, outperforming several other curved GNRs reported via conventional Scholl reaction.</p>

Topics

• impedance spectroscopy
• compound
• single crystal X-ray diffraction
• single crystal
• Carbon
• mobility
• density functional theory
• Nuclear Magnetic Resonance spectroscopy
• scanning tunneling microscopy